OpenType features in this family

• c2scc2sc31 substitutionsABCDEFGHIJKLMNOPQRSTUVWXYZÆÐØÞABCDEFGHIJKLMNOPQRSTUVWXYZÆÐØÞUse in sampler
• casecase35 substitutions()+-<=>@[]{}~¡«¬±·»¿×÷‐‑–—―•‹›()+-<=>@[]{}~¡«¬±·»¿×÷‐‑–—―•‹›Use in sampler
• ccmpGlyph composition2 substitutions · contextualijijUse in sampler
• dligDiscretionary ligatures2 substitutionsact strict spectrum fact stoneact strict spectrum fact stoneUse in sampler
• dnomdnom10 substitutions01234567890123456789Use in sampler
• fracfrac11 substitutions · contextual/0123456789/0123456789Use in sampler
• ligaStandard ligatures5 substitutionsffi ffl ff fi flffi ffl ff fi flUse in sampler
• numrnumr10 substitutions01234567890123456789Use in sampler
• onumonum10 substitutions01234567890123456789Use in sampler
• sinfsinf10 substitutions01234567890123456789Use in sampler
• smcpsmcp31 substitutionsHamburgefonstivHamburgefonstivUse in sampler
• ss01Alternate a1 substitutiona banana at a bakera banana at a bakerUse in sampler
• ss02Alternate g1 substitutiona gigantic gaga gigantic gagUse in sampler
• subssubs10 substitutions01234567890123456789Use in sampler
• supssups10 substitutions01234567890123456789Use in sampler
• tnumTabular figures10 substitutions01234567890123456789Use in sampler
• zerozero1 substitution00Use in sampler

Left: feature off. Right: on. Substitutions read from the font's GSUB table.

Known limitations

• Unhinted: relies on the rasteriser's own anti-aliasing. Windows GDI aliased rendering below about 11 px will look uneven.
• Static cuts only (Light, Regular, Medium, SemiBold, Bold, each with an italic); no variable font and no optical sizes: one design for 12 to 18 px, hairlines are too fine for text below about 11 px and heavier than needed above 48 px.
• Spacing and kerning are computed (area method plus collision floor) and checked on proof sheets, not tuned pair by pair; expect a few pairs a hand kerner would change.
• Serifs, flags and beaks are analytic shapes with simple bracket curves, not drawn per letter: the family is consistent but not as individually shaped as a hand-drawn text serif.
• The italic redraws a b d e f g h i j k l m n p q r t u v w y; capitals, o c s x z and figures are the roman skeletons sheared (no swash or italic capitals).
• Small caps, oldstyle figures, superiors and fractions are the same skeletons redrawn at reduced size, not redrawn by hand; small caps are a little wide and accented capitals have no small cap form (c2sc and smcp reach only the base letters).
• Accents are deliberately lighter than the weight on the heavier cuts (pen capped at 44 units half width) and the letters ß, ð, þ and ł are serviceable rather than carefully drawn.
• Ink traps are automatic and small (about 7 units in Regular, 19 in Bold): invisible below about 40 px.
• Vietnamese stacked tone marks are placed by fixed rules, not drawn per letter; they are legible but not refined.
• Symbols, currency, arrows and maths are adapted from the sibling sans skeletons with an even pen; they are the least refined part of the set.
• Latin only: no Greek, Cyrillic, African or Pinyin Latin letters.
• Name 'Dioptra Serif' was not checked against any trademark or font database.

The designer's own list, copied unchanged from the font's hand-off manifest.

Coverage by Unicode block

• Basic Latin94 / 94
• Latin-1 Supplement94 / 95
• Latin Extended-A128 / 128
• Latin Extended-B10 / 208
• Spacing Modifier Letters8 / 80
• Combining Diacritical Marks19 / 112
• Latin Extended Additional97 / 256
• General Punctuation34 / 98
• Superscripts and Subscripts17 / 42
• Currency Symbols2 / 33
• Letterlike Symbols1 / 80
• Arrows10 / 112
• Mathematical Operators9 / 256
• Geometric Shapes1 / 96
• Alphabetic Presentation Forms5 / 58